Flour, butter, and cream cheese - How does this expand?

Toast

During Christmas I made a pastry which has a dough made of the things listed, with a filling of jams or whatever. What surprised me is that, though the dough is only those things and has no leavening in any form, they rise considerably. As much a 4 times the original width, when laid flat and unobstructed.

What in the world is causing this reaction?

The dough did sit overnight in the refrigerator. Could there be yeast floating around in my kitchen from all my bread baking which got in there? Can that even happen? 

More precisely, moisture is trapped between the layers of dough and fat, and this moisture turns to steam and expands, due to the oven heat.

...that when you whip soft but not liquid butter with flour, air pockets are formed in the dough and these expand in baking.

I noticed the nice light (considering the amount of fat) texture of the ITJB cream cheese short dough when I made the mini-schneckens.

BTW, croissants without leavening would be something other than croissants.

Glenn

it's mixed to combine, and generally speaking you can either whip fat and sugar (creamed cake) or eggs and sugar (sponge cake) to incorporate air.  the flour (well-sifted) is normally combined after the aeration takes place and after beaten egg (creamed cake) and flavorings have been incorporated into the  mass. flour is really too dense to aerate with fat. woof! woof!

Stan

 

Hello again, no, the dough that I made was not laminated, simply mixed. Not a pariticularly light or airy dough, either.

But it seems that Elagins has already answered my question. I never would have expected it would have these results. It is interesting.

I wonder if the pH could have something to do with leavening, too? I've used a dough made with flour, sour cream and butter, and that expanded too, although not four-fold. From what I remember, it came out with small air pockets, somewhat larger than in shortbread. Both cream cheese and sour cream will have some lactic acid in them, would thatreact with something or decompose with heat to produce a bit of gas?